1. Field of the Invention
The present invention relates to communication networks, and more specifically to a method and apparatus for providing different quality of services (QOS) to different point-to-point sessions.
2. Related Art
Point-to-point sessions are often set up between remote systems (e.g., personal computer systems at homes) and communication networks. A PPP session generally allows data transfer between a remote system and a termination device situated at the edge of a communication network. Point-to-point protocol (PPP) described in request for comment (RFC) 1661, available from www.ietf.org, is a common protocol using which point-to-point sessions are established.
The termination device usually provides additional communication to enable a remote system (at one end of a session) to communicate with a target host as is also well known in the relevant arts. The communication between a host and a remote system forms the basis for several user applications. As the host systems and remote systems are at either end of corresponding applications, the two systems are commonly referred to as end systems.
A prior communication network may be designed to provide the same quality of services (QOS) to several point-to-point sessions. While such a model is simple to implement and has the related advantages, it may not be suitable in some environments. For example, a point-to-point session used for real-time or interactive applications may need low latency and predictable high bandwidth, while a session used for batch applications may merely need bandwidth unused on a communication network.
In one embodiment, network devices located at the edge of a communication network may be designed to examine each datagram related to a point-to-point session and provide differentiated services to each packet. As used in the present application, a datagram refers to fixed (e.g., ATM cells) or variable length (e.g., Internet Protocol Packets) data units used for communication between remote systems and communication networks. However, the overhead resulting from the examination of each datagram may be unacceptable at least in some environments.
Accordingly what is needed is a method and apparatus which enables different QOS to be provided to different point-to-point sessions while minimizing the overhead on the network devices.